The invention relates to couplings in general, and more particularly to improvements in couplings which can be used to establish a separable fluidtight connection between an end portion of a first tubular component (e.g., a nipple at one end of a metallic or plastic pipe) and an end portion of a second tubular component (for example, one end portion of a flexible elastic hose). Such couplings can be used under the hoods of motor vehicles and for many other purposes.
Commonly owned U.S. Pat. No. 4,486,034 to Sauer discloses a hose coupling wherein a sleeve-like coupling member has a cylindrical outer portion which surrounds the end portion of a hose and a cylindrical inner portion which is surrounded by the end portion of the hose and surrounds the end portion of a pipe or another tubular component which is to be secured to the hose. The free end of the pipe has a ring-shaped retainer which is engaged by the free end of the cylindrical inner portion of the sleeve in assembled condition of the coupling to prevent extraction of the pipe from the sleeve. The sleeve includes U-shaped prongs each having an outer leg forming part of the outer portion and an inner leg forming part of the inner portion. The end portion of the hose is clamped between the legs of the U-shaped prongs. The free ends of the inner legs of the prongs bear against the retainer if the hose is pulled in a direction to move it off the end portion of the pipe or vice versa.
A drawback of the patented coupling is that the end portion of the hose can be properly clamped between the inner and outer portions of the sleeve only if the wall thickness of the end portion of the hose is within a predetermined range of wall thicknesses. If the wall thickness of the end portion of the hose is excessive, the coupling can be assembled only with the exertion of a considerable force in order to slip the sleeve onto the end portion of the pipe. Moreover, the clamping action of the sleeve upon the end portion of the hose is unpredictable and unreliable if the wall thickness of the end portion of the hose is less than the minimum value of the aforementioned range of acceptable wall thicknesses.